DE1447703A1 - Process for making light photographic papers transparent - Google Patents

Description

PATENT OFFICE UTE * '

dr. w. Schalk dipl.-ing. peter Wirth

DIPL.-ING.G. E.M.DANNENBERG DR. V. SCH MI ED-KOWARZI K

6 FRANKFURT AM MAIN

CR. ESCHENHEIMER STR. S9 POST CHECK ACCOUNT: 15628 FR ANKFURT / MAIN bK / oK.

0-298

General Aniline & Film Corporation HO West 51st Street

New York 20, N.Y. /UNITED STATES

Process for making light photographic transparencies papers

The present invention relates to a method and a preparation for preventing curling in the case of being made transparent Intermediate paper for Diazotype process.

Paper made transparent is known to be particularly suitable for a wide variety of photographic interleaving papers Process, and Θ3 are many processes known to paper for the purpose of To treat see-through or making transparent. The known Processes for making paper transparent have usually been done by treating the paper with a so-called "transparent" making solution "which consisted of a solution of a suitable resin in a hydrocarbon solvent. Though many Resins that can be used for clarifying paper include the most common clarifying solutions Vinyl resin, including homopolymers and copolymers of styrene, methylated styrene, methacrylic acid, etc. As Hydrocarbon solvents are usually toluene, xylene-? solvents, naphtha, etc. used.

809811/0907

Although many of the previously used, transparent ones Processes generally produced a paper of acceptable quality, particular difficulties arose when the paper should be used for photographic purposes. In general When using relatively heavy paper, the curling of the translucent paper will not be a problem because it Has sufficient internal strength so that it does not tend to curl due to the resinous solutions applied. However not all photographic processes allow the use of the relatively heavy paper, and if a transparent one, light · paper (6.35-7 »25 kg) must be used, this will The problem of curling increases because the light paper is more sensitive to heat and moisture than conventional paper Weight.

A photographic process in which the use of light, paper made transparent is the production of diazotype intermediate papers for the two-component process.

The two-component diazotype papers are usually developed by passing the sensitized side of the paper at a temperature of up to T07 ° through a chamber saturated with ammonia and water vapors. This places a heavy load on the front of the diazo paper, which causes a backward curl as the paper exits the development chamber. For paper of usual weight the reverse curl is limited (up to mm 25) and atjellt not a problem. However, in leibhteren intermediate papers I3T "Us i? Tfckwärts- Eüirollen much stronger and gives ofjf eiiie to the rear rolled role · This is it Impossible ■ "«: * ■>, .the paper

^ w

to be stacked, making the handling for the operator of each machine

becomes extremely difficult.

This curling of diazotype papers obtained from diazotype copiers leak is known to be a temporary curl that quickly disappears when the vapors develop Leave the film or sheet and the paper adapts to the conditions of the environment. At this point the paper takes its permanent shape, which is often flat, but sometimes can be curled up to a certain extent towards the front or back. The optimal curling properties of a diazotype paper can be such that it emerges flat from the development chamber and also remains flat when it reaches equilibrium with its surroundings.

That is, good curling properties of a diazotype paper consist in the fact that it comes from a copier with a reverse curling does not emerge more than 40 mm, so that stacking can take place and that θβ a constant after equilibrium has been reached Curling not reached more than 15 mm. According to the usual Saxis translucent papers with light weight can are difficult to provide with such curling properties; however, this is possible with the method according to the invention.

It has been found that curling in transparent diazotype intermediate papers can be reduced significantly by incorporating eXn glycol into the resin solutions commonly used for transparency. Without wishing to be bound by any particular theory, it has been found that when a glycol is added to a solution that makes it transparent, the properties of the paper curl are sufficiently controlled to prevent the

- 809811/0907. ·

Paper for many ^ otogr-ayhiyche procedures, especially for. to make the diazotype process particularly suitable.

The glycols usable in the present invention are normally liquid and have a boiling point above about 180 °. Suitable glycols are, for example, diethylene glycol, propylene glycol; Dipropylene glycol, Triethylene glycol, 1,2-butanediol, 1,3-butanediol, 1-butanediol , 4, 1,2-pentanediol, 1,3-pentanediol, 2,3-pentanediol, 1,6-hexanediol, 2,3-hexanediol, etc. "

will

The inventive method / carried out by the selected Glycol of a common translucent solution admits, the paper is thoroughly impregnated with the solution and'through Eliminating the low boiling solvent dries · The

Glycol by weight can be added in an amount between 0.12-0.5 / part per part by weight of the resin used in the translucent solution? be joined. The paper is then treated with the solution for as long as sufficient impregnation of the paper is ensured (about one week when using the "Haßp.aek ¹¹ method), whereupon the paper is coated with the sensitizing preparation after drying.

Diazotype preparations which can be used in the dry diazo process are known; suitable couplers include 2,3-diox3-am-S * ialine-6-8ulfonic acid j 2-amino-8-naphthol-3,6-disulfonic acid j 2,3-dioxynaphthalenes 2,7-dioxynaphthalenes; 1,7-aminonaphthol-2-oxy-8-biguanidj resorcinol, phloroglucinol! m-Oxyphenyl- 'harnstoffü Aoetoacetanilid \ 7-0xy-1,2-naphthimidazole, etc. ■ Suitable typical diazo compounds are derived from the usual p-phenylenediamines, such as p-amino-N-methylanilini

809811/0907

_ ς -

p-amino-N-dimethylaniline; p-amino-N-ethylaniline; p-amino-N-oxyethylaniline; p-amino-N-ethyl-IT-oxyethylaniline; 4-amino-2-methoxy-1 -cyoloiiexylaniline etc.

The following examples illustrate the present invention without limiting it.
example 1

A common translucent solution was made as follows:

Naphtha 25 ecm

Polystyrene 40 g

Isopropanol _ 25 ecm

10 ecm of dipropylene glycol were added to this solution

A 7.25 kg rag paper was immersed in the solution and a Week wet? whereupon it became transparent. Then it was dried by allowing the naphtha and isopropyl alcohol to evaporate heated. * ("wet packed")

The transparent paper was wetted with the following solution on the xiuQkaeite.

Water 100 ecm

Ethylene glycol 4 ecm

Saponin 0.15g

Then the paper was dried and treated with the following diazotype preparation overdrawn:

water

citric acid
Thiourea
Resorcinol

4- (N-methyl-N-oxyethyl) aminobenzodiazonium chlorozincate

Saponin

80981 1/0907

100 ecm 7th S. 5 G 2 G 4th G 1.5 G

mtm Q ^

The paper was dried and covered under a translucent Original exposed; then the exposed material was developed with ammonia in a conventional white copier. That Paper emerging from the ammonia chamber showed a temporary curl of 20 mm, which allowed for stacking. After the paper When equilibrium was reached, the permanent curling of each piece was 10 mm.

The effect of the glycol on the curling is indicated by the following Comparison experiment shown.

Example 1 was repeated except that the diethylene glycol was omitted from the clarifying solution. After checking of the paper it was wetted and sensitized as above and exposed. That emerging from the amiaonia chamber Paper showed "however a temporary curl of 50 mm, which made appropriate stacking almost impossible and the entire work process hindered

From this it can be seen that the addition of the glycols according to the invention to transparent solutions effectively reduces the curling properties of non-woven paper and makes the paper _{particularly suitable for c} diazotype processes.

80981 1/0907

Claims (7)

Claims
1, - A process for making light photographic papers transparent while at the same time reducing the tendency to curl during use, characterized in that the paper is treated with a transparent solution of a resin in a low-boiling hydrocarbon solvent which contains a glycol boiling above approximately 180 °, impregnated and dried by removing the solvent. 2.- The method according to claim 1, characterized in that the Glycol is used in an amount of 0.12-0.5 part by weight per part by weight of the resin. 3 · - Method according to claim 1 and 2, characterized in that a vinyl polymer is used as the resin. 4 · - Method according to claims 1 to 3 »characterized in that as glycol ethylene glycol, propylene glycol or dipropylene glycol is used· 5 · - Process but production of diazotype intermediate papers with a reduced tendency to curl during processing, characterized in that a light paper with a translucent solution of a resin and a base boiling organic solvent containing a normally liquid glycol with a boiling point above about 180 °, impregnates »the paper to remove the low boiling point Solvent dries and the paper with a diazotype preparation sensitized. 809811/0907 6.- The method according to claim 5 »characterized in that ethylene glycol, propylene glycol or dipropylene glycol is used as the glycol will. 7.- Light-sensitive diazotype intermediate paper (intermediate copy paper), consisting of a transparent carrier containing a resin and a small amount of a normally liquid one Contains glycols with a boiling point above about 180 ° and is coated with a sensitizing diazotype preparation, the Diazotype intermediate paper has a reduced tendency to curl during processing. The patent attorney: 809811/0907